Custom markers Ionic

Ionic Framework ionic-v3
1

Hi guys, do you know what should be the location for the custom markers images and what type of img should it be(png,svg)?

if i put it in assets/img folder marker shows on browser but not on device

   var marker = new google.maps.Marker({
	position: myLatLng,
	map: this.map,
	title: 'Pumpa',
	icon: {
		url: "../assets/img/2.png",
		scaledSize: new google.maps.Size(30, 30)
	}